Eccentrical cutting-bit.



PATBNTED FEB. 55, 1907. NDER.

J. H. TOMBRAIGEL & J, F. $01111 ECGENTRIGAL CUTTING BIT.

APPLICATION IILED MAY 1, 1906.

TEFL- INVENTORS fi k 7262 721 .362

W/ TNE SSE S om 251a 91 6 k 921; neZez' A TTORNEYS UNITED STATES PATENT OFFICE.

JOSEPH H. TOMBRAGEL AND JOHN F. SCHUNDER, OF COVINGTON, KENTUCKY.

ECCENTRICAL CUTTING-BIT.

Specification of Letters Patent.

Patented Feb. 5, 1907.

I Application filed May 1, 1906. Serial No. 314,643.

To [LZZ whom it may concern.-

Be it known that we, J OSEPH H. TOMBRA- GEL and JOHN F. SCl-IUNDER, both citizens of the United States, and residents of (lovington, in the county of Kenton and State of Kentucky, have invented a new and Improved Eccentrical Cutting-Bit, of which the following is a full, clear, and exact description.

This invention relates to bits used in boring holes in wood or metal; and it is especially useful in connection with a device of this class, cutting a perforation of greater diameter than the normal dimensions of the bit.

The object of the invention is to provide novel details of construction for a bit of the character indicated which are simple, durable, and easily adjusted, enabling the lateral adjustment of the bit to the axis of its shank, whereby the bit will bore a hole of any desired diameter and depth within its capacity.

A further object of the invention is to provide a bit-stock that may be readily adjusted to hold the cutting-bit centered or alined with the axis of the stock or shank, so that it may be used to bore a hole equal in diameter to the size or width between the cutting edges of the bit.

The invention consists in the construction and combination of parts, to be more fully described hereinafter and particularly set forth in the claims.

Reference is to be had to the accompanying drawings, forming a part of this specification, in which similar characters of reference indicate corresponding parts in all the iigures.

Figure 1 is a partly-sectional side view of the improved bit, showing the bit-shank and cutting-head of the bit adjusted for boring a hole of greater diameter than that of the cutting-head. Fig. 2 is a horizontal cross-section on the line 2 2 of Fig. 1. Fig. 3 is a view similar to Fig. 2, showing the parts in a different alinement; and Fig. 4 is a horizontal crosssection on the line 4 4 of Fig. 1.

Referring more particularly to the parts, we provide a cylindrical bit-stock 1, having a longitudinal eccentric bore 2 at the lower end and which has formed on the same end an exterior thread 3. The center line of the bore 2 is parallel to and slightly spaced from the center line of the bit-stock. The bitshank 4 is cylindrical and near the upper portion thereof is an integral radial shoulder or flange 5, which is adapted to abut against the lower side of the bit-stock 1. Extending above the flange 5 is a stud 6, smaller in diameter than the bit-shank 4. The other end of the bit-shank terminates in a cuttinghead 7, as shown. The coniform body of the cutting-head 7 is longitudinally channeled at diametrically opposite points to provide two similar cutting lips or edges 8, and tie concave lower end of the cutting-head is formed of radial thin cutters 9, which cut a clearancegroove, this being essential if the bit is employed for forming flat-bottomed mortises, for instance, in wood material. The cutting head 7 is of ordinary form, and other shapes of the same may be substituted, the form described being snown merely to illustrate the application of the improvement.

Upon the stud 6 is mounted a sleeve 10, which has a longitudinal eccentrical bore 11 for this purpose and which is adapted to fit into-the bore 2 of the bit-shank. We provide a cylindrical member 12, which is provided with an interior thread 13 near the up per portion and is adapted to be screwed onto the bit-stock 1. The member 12 has a longitudinal bore 14 and interior shoulder 15, which is adapted to engage with the flange 5 of the bit-shank and force the latter against the bit-stock when the member 12 is screwed upon the bit-stock, thus jamming said flange in the position shown in Fig. 1, and thereby holding the bit-stock and the bit-shank relatively immovable. In the lower end of the member 12 are formed opposite kerfs 16 for the engagement of a suitable implement which will enable the turning movement of the member in either direction and also enable the holding of the same stationary while the shank or stock, or both, receive rotatable adjustment. lndicatinggrooves 17 may be formed in the lower ends of the stock 1 and the sleeve 10, across the same, these marks defining the points of greater projection had by the eccentric swells 18 and 1 9 on the members 1 and 10. The alinement of both sets of grooves indicates that the bit-shank and are on the same side of the true axis and in alinement, thus placing the axis of the bit/ shank a maximum distance from the axis of the bit-stock. Obviously if the swell 19 on the sleeve 10 is turned partly around and away from the degree-marks 17 on the stock and the latter is maintained without change in projection from the axis of the shank 4 the turning movement of the sleeve will reduce the lateral projection of the cutting-head correspondingly. It will be seen that by a turning adjustment of the sleeve and stock or either one independently more or less lateral disposal of the cutter-head on the bit-shank may be effected, andthe eccentric action of the cutting-head will correspondingly increase the diameter of the hole bored by the said cutter-head. 7

It will be understood that incutting a hole greater in diameter than the width of the out tor-head that-but one edge of the head is used and that when this becomes worn or dulled the cutter may be simply reversed, first loosening the member 12 by unscrewing it and the other edge of the cutter-head then employed. The stock of the bit afl'ords means for connecting the cutter-head with means for its rotation and longitudinal move ment and is preferably formed as shown in Fig. 1. When the swell 19 on the side of the sleeve 10 is positioned directly opposite from the swell 18 on the stock 1, if said swells are suitably proportioned in thickness at their crowns the axis of the bit shank 4 may be disposed centrally within the exterior wall of the stock 1, as shown in Fig. 3, whereby the connection of the latter with a rotatable chuck on the drilling-machine will adapt the cutting-head to rotate without lateral wabble, and consequently will bore a hole equal in diameter to the width of the cutterhead.

Having thus described our invention, we

stock having a longitudinal eccentrical bore,

an eccentric sleeve in said bore, a shank having a stud in said sleeve, and a flange adapt ed to hold said sleeve in said bore and to abut against said stock, a member adapted to be screwed onto said stock, and having a shoul+ der adapted to engage with said flange to jam the same against said stock.

3. An eccentrical cutting-bit, comprising a stock longitudinally and eccentrically bored and having a thread formed on an end there of, an eccentric sleeve in said bore, a shank having a stud in said sleeve, a flange adapted to abut against said stock, a cutter, and a cylindrical member interiorly threaded and adapted to screw onto said stock and having an interior radial shoulder adapted to engage with said flangeand jam the same against said stock, said member further having notches in" one end to facilitate the turning thereof, said sleeve and said member having indicating marks to define the relative positions thereof.

In testimony whereof we have signed our names to this specification in the presence of two subscribing witnesses.

JOSEPH TQMBRAGEL. JOHN F. SCHUNDER. WVitnesses:

LE0 SMIf IH K-ITTIE E. HIGKMAN. 

